Re: Web conferencing
Larry Masinter (masinter@parc.xerox.com)
Tue, 10 Jan 1995 21:41:53 +0100
For active documents that change when the stock price changes or
involve a conference between multiple participants, I like the idea of
extending "expires:" to be (point to) an expression, the variables of
which can include things like 'the current time' or 'the location of
the browser' (for mobile applications) or other items which have a
URN. The resolution strategy for dynamic variables is that you get the
URN, you decide if this is a local one (i.e., that you get from your
environment, in which case you watch it locally) or a remote one (in
which case you have to resolve the URN into something that you can
watch, e.g., the time, which means that you poll.)
This scheme evolves gracefully: dumb clients can always poll, smart
ones can know more about two-way communication between their
environment watcher and the servers that control those state
variables.
(This is a variation of the idea in <URL:http://www.cs.washington.edu/
homes/voelker/mobisaic/abs-mobile94.html>